Ontario Mineral Inventory

Ontario Geological Survey
Permanent Link to this Record: MDI000000001966

Record: MDI000000001966

General

Commodities

Primary Commodities: Gold

Location

Township or Area: Brothers

Latitude: 48° 40' 16.14"    Longitude: -85° 49' 18.51"

UTM Zone: 16    Easting: 586741   Northing: 5391570    UTM Datum: NAD83

Resident Geologist District: Thunder Bay South

NTS Grid: 42C12NW

Point Location Description: M2614

Location Method: Other

Exploration History

1948: Lake Superior Mining Corp. Ltd drilled 2 DDH totalling 56.1 m. 1950: J. Skopyk carried out stripping, trenching, and sampling. 1981-1991: Lac Minerals conducted line cutting, geological mapping, magnetometer, IP, CSAMT, mise a la masse, maxi probe, humus geochemistry, trenching, overburden drilling and diamond drilling totalling 30,493 metres in 145 holes. Most of the diamond drilling was concentrated along the Upper Anomalous and Gouda Lake Horizons. In 1991, the Supreme Court ruling against Lac resulted in Lac losing interest in the White River Property.1992-96: Placer Dome optioned the property completing an airborne radiometric survey and reconnaissance scale mapping plus humus sampling surveys over a portion of the "Tail". Placer established a 200 m spaced grid and conducted 134 km of geological mapping at 2 500 scale along with humus geochemical sampling in three selected areas culminating with diamond drilling of 16 NQ holes for a total of 6,096 metres. 1996: Barrick completed a limited amount of additional exploration on the property, including a prospecting program along the eastern extension of the Gouda Lake alteration zone, and a revised compilation plus lithogeochemical sampling program of two of the more prospective mineralized zones. 1998: Lac Exploration Inc. did a compilation of previous work and a lithogeochemical sampling program. 1999-2004: Teck Exploration Ltd completed geological mapping and sampling, soil and humus sampling, limited line-cutting and logging and sampling of selected Lac diamond drill core. Teck completed an initial phase of diamond drilling in 2000 consisting of 8 holes (2 032 metres) testing selected targets in the western half of the property. The winter 2001 drill program tested targets in the eastern portion of the property with 9 drill holes totalling 4 429 m. Teck returned in 2003 to follow up a 39 m anomalous As-W intersection encountered in hole WR01-02 in the footwall sediments to the contact with the Cedar Lake Pluton with 3 drill holes totalling 1248 m. 2010: MetalCORP Ltd. drilled 1 DDH totalling 1528 m.

Assessment Work on File

Geology

Province: Superior

Subprovince: Wawa

Terrane: Wawa-Abitibi

Belt: Schreiber-Hemlo

Geological Age: Archean   Geochronological Age: 2694 +/-1.1 Ma   

Geology Comments

Jul 13, 2016 (Andrew Tims) - The Egg Lake area is comprised of the Cedar Lake Pluton in the northern half and is bounded to the south by the Hemlo Fault Zone (HFZ). The majority of the rock in this area consists of clastic metasediments, with minor amounts of iron formation. Felsic to intermediate volcanics and mafic volcanics, the latter beingalong the HFZ, all occur in minor amounts. Numerous feldspar porphyry dykes intrude throughout the area as well as Proterozoic diabase dykes, most of which are highly magnetic. Structurally, the area is complex, with isoclinal folds present in individual lithological units, and as part of larger scale tight folds;

Lithology

Mineralization

Mineralization Comments

Mar 13, 2019 (Andrew Tims) - Two distinct zones of mineralization in the Egg Lake area include the Egg Lake Horizon and a structurally overlying pyritic horizon, referred to as the Upper Anomalous Horizon. Drill intersections by Lac returned assays of up to 1.35 g/t Au over 7.0 metres (including 4.95 g/t Au over 1.0 metre) from the Upper Anomalous Zone. Surface grab samples of the Upper Anomalous Horizon taken by Teck in 2000 returned values as high as 2.85 g/t and 1.27 g/t Au. Gold mineralization is associated with prominent arsenic and mercury anomalies.

Mar 13, 2019 (Therese Pettigrew) - In the Egg Lake area, 14,200 m of diamond drilling tested 5.0 km x 1.5 km x 200 m and yielded a best value of 5.14 g/t Au over 1.0 m, with most values in the 0.4-0.7 g/t Au as isolated samples (Assessment file 42C12NE2001). The sulphide mineralization in the 2010 MetalCORP drill hole is typically hosted by metasedimentary rock and is encountered in four separate horizons, present as meter scale intervals of 1-5% disseminated to layered pyrite in association with quartz and sericite. Sphalerite, pyrite, minor chalcopyrite, and trace molybdenite are present on fracture surfaces locally throughout the hole. Minor amounts of pyrite with lesser sphalerite and molybdenite was also encountered in some of the pegmatitic dykes (Assessment file 20000004620).

Mineral Record Details

References

Map - Geological Compilation of the Eastern Half of the Schreiber-Hemlo Greenstone Belt

Publication Number: M2614 Scale: 1:50,000    Date: 2000

Author: Muir T.L.

Publisher Name: Ontario Geological Survey

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Ministry Contact Information

For detailed information regarding this mineral record please contact the Thunder Bay South Resident Geologist District Office